Wanted to buy an item I had advertised in the classifieds by messaging me in the app. Then said to text him outside of app to provide info. . Then said his job had a busy schedule and that he would send a cashiers check. Very fishy, watch out for doing transactions outside of the security of the classified app.  Here's the transcript of the message:
"Thanks for the prompt response. I will be  buying this from you,  kindly withdraw the advert from offerup and considered it sold. My wife  will be overwriting the payment asap but he will be paying with a certified check from our Bank and it will  deliver to you via United Parcel Service (UPS), so  I'll need you to provide me with the following information to facilitate the mailing of the check... And am offering additional $70 with the original price to have this asap.

Name to be on the payment ...........
Address to mail the check to .............
City, state and Zip code .............
Final Asking price...................
Cell phone # to text you on ................

I will make arrangements for the pick up as soon as you have your check clear, due to my work frame and my Kids,  I will not be able to come with the cash and pick it up myself , so my Wife will mail the check and have someone pick up the item after the check clear., Reference to your offerup post  am completely satisfied with it  and the payment will  be deliver within 48 hours.. God Bless"